Excerpt
Teddy Roosevelt was frustrated by this lack of interest, but in the process he also discovered one meaning of the notion of American exceptionalism: that old world powerpolitical reasoning in support of global engagement held little allure for the American people, being largely self-sufficient, protected by oceans East and West, with friendly and weaker neighbors to the North and South. So TR tried to tap into a broader sense of American identity to help mobilize public support. He was the first US leader to propose a league of nations, as early as 1904, saying that it would work like that familiar American institution, "a posse comitatus."
Woodrow Wilson, of course, went Roosevelt one better on the ideational level, promising to make the world safe for a whole panoply of American values and to enshrine the promise in the League of Nations. And so we got our first whiff of multilateralism ñ which was quickly defeated in the Senate by the unilateralists, led Henry Cabot Lodge. Isolationism ensued as a consequence of Wilsonís defeat; it was not its cause.
Citations
Ruggie, John Gerard. "American Exceptionalism and Global Governance: A Tale of Two Worlds?" Working Paper No. 5. CSR Initiative at the Harvard Kennedy School, April 2004.